The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
The present invention pertains to instrumenting platforms to acquire data. Acquired data may be recorded for later playback as well as provided to a platform operator in real time in multiple formats, such as warning lights, digital, video, or audio. A specific application employs a flight-certified missile launcher modified to hold instrumentation conforming, at least in part, to the launcher""s internal dimensions, while enabling autonomous display and recording of data that may occur during severe environmental stress of the aircraft carrying the modified launcher.
Military aircraft may carry multiple missiles, an example being the air-to-air AIM-9X SIDEWINDER. An aircraft""s missile station may combine a missile and its corresponding missile launcher, such as the LAU-7 missile launcher pod for the AIM-9X carried on an F/A-18. A fire control system, responsive to a pilot""s input, communicates with each missile station to monitor status, prepare for launch, and launch. A weapon system interface transfers the commands from the fire control system as data for monitoring and controlling the missile stations.
The weapon system interface includes an umbilical and may include a data link. The umbilical provides communications between the fire control system and missile prior to launch, while the data link provides communications post-launch to some missile types, the AIM-9X not being of this type. For xe2x80x9con-rangexe2x80x9d testing, the AIM-9X may have a telemetry data link installed in place of the warhead for the purpose of telemetering data to a receiver station on the range. To preserve resources and reduce costs, many flight tests of missiles are xe2x80x9ccaptive carryxe2x80x9d tests, i.e., the missile is not launched but its seeker is activated and the aircraft flown as a simulated missile to determine missile seeker performance against a variety of targets and target backgrounds. Such captive carry missions may also include training exercises for pilots, weapons controllers, load crews, test range instrumentation personnel, or other operators, as well as missile system performance testing.
For conventional missiles, a simple connector can be used to route data using cabling pre-installed in the aircraft wings. Thus, a functioning missile may be represented as a simulation to the aircraft""s fire control system. While this capability has achieved some success, it has inherent disadvantages in capturing the data acquired during the test or simulated operation. For example, it requires a ground telemetry station to capture and record data for real-time data acquisition and post-analysis.
Various systems have been employed to simulate missile functions during training and testing, both on the ground and in the air. One such device for simulating pre-launch conditions only, is the Integration Test Vehicle (ITV), a specially modified AMRAAM missile. The ITV is completely inert, replacing the warhead with a telemetry unit. However, a simple connector cannot be used with AMRAAM adapted missile stations since the interface to the AMRAAM includes a more complex combination of discrete signals and MIL-STD-1553 serial data with specific timing requirements imposed thereon. Other simulators incorporate unique software specifically designed to function only with a specific missile variant as installed on a specific aircraft variant.
A conventional test apparatus and method is represented by that of U.S. Pat. No. 5,614,896, Method and System for Aircraft Weapon Station Testing, issued to Monk et al., Mar. 25, 1997, in which each of a number of an aircraft""s weapon stations is able to be function tested via a portable test station incorporating a common electronics module and interchangeable mechanical fixtures. This testing may be done only while the aircraft is on the ground, however.
One of the ways to conduct tests of a missile""s function is to simulate an actual launch from an aircraft. To simulate a missile while airborne, various simulators have been devised, an example being one represented in U.S. Pat. No. 5,624,264, Missile Launch Simulator, issued to Houlberg, Apr. 29, 1997, and incorporated herein by reference. This simulator provides a realistic simulation of the launch of a missile from an aircraft weapon station incorporating a launcher. The flight of the aircraft and missile are simulated on the ground, however, with vibration and other environmental forces encountered by an actual flight estimated mathematically, if at all.
U.S. Pat. No. 5,591,031, Missile Simulator Apparatus, issued to Monk et al., Jan. 7, 1997, describes an apparatus to be used for pilot training that incorporates a pre-launch module, and a data link and data capture module in an inert form-factored missile body for recording all data transfer between the aircraft and the apparatus during the flight. The modifications are incorporated in the missile itself, rather than the aircraft""s onboard launcher, hence, only modified missiles are suitable for these training missions.
For each of the above situations, a common disadvantage is the inability to take a missile from stock, mount it on an aircraft and fly it in an xe2x80x9call outxe2x80x9d captive test. The present invention overcomes this and other limitations of the above conventional systems while also providing a new capability for a pilot or other operator to redirect a mission based on onboard real time inputs.
A preferred embodiment of the present invention provides a method and apparatus for configuring an instrumentation package on an aircraft to acquire data autonomously while airborne. The instrumentation package is specifically configured to fit within the interior volume of an existing structure that has been certified at least as to its strength, weight, center of gravity (COG), and Moment of Inertia (MOI). Devices that may exist within the interior volume of the structure may be removed to provide space for the instrumentation. An example existing structure is a flight certified missile launcher (launcher pod) carried on an external stores station of a high performance aircraft. The launcher pod serves as a launcher for a missile such as an air-to-air missile used by the U.S. military. Some launchers have an xe2x80x9cair bottlexe2x80x9d installed to facilitate cryogenic cooling of the infrared detector on conventional missiles such as the Navy SIDEWINDER AIM-9M. High pressure gas flows from the launcher to the AIM-9M via a thin metal tube in the same umbilical that carries electrical cabling to the missile from the aircraft. The AIM-9X version of SIDEWINDER has a xe2x80x9cclosed cycle coolerxe2x80x9d internal to the AIM-9X, thus the air bottle is not required to be installed in the launcher when an AIM-9X is carried on the launcher station. This air bottle, normally filled with nitrogen (N2) at high pressure, thus, hereinafter referred to as an N2 bottle, and its supporting structure may be removed and replaced with the form-fit instrumentation package.
The instrumentation package may comprise:
a digital recorder that has suitable flash memory, such as flash RAM, for a typical airborne test mission of one hour or more;
circuitry for connection to the recorder, various power supplies and an interface to the aircraft and at least one missile that is carried on the weapon station carrying the launcher; and
connections from the circuitry to various sources of data to include aircraft avionics, displays, missile seeker and controls, and power supplies both internal to the launcher pod and supplied by the aircraft.
The instrumentation package may be configured without changing the external physical configuration of the aircraft or other platform on which it is installed. Further, the installed configuration may minimize requirements for additional certification of the existing structure, e.g., a launcher on a high performance aircraft. This may be accomplished by carefully matching weight, center of gravity (CG), and moment of inertia (MOI) of the instrumentation as installed to that of a standard LAU-7 missile launcher pod. The instrumentation may be used to acquire data autonomously for measuring performance of a system, such as a missile that is being operated in a xe2x80x9ccaptive carryxe2x80x9d test while the aircraft is performing maneuvers simulating a missile fly out as well as normal missile operation when acquiring and tracking targets while onboard the aircraft. The instrumentation, as so configured, provides a capability of flight testing a missile and acquiring test data without the need for telemetry of acquired data to a ground site. This capability further provides the flexibility of testing in scenarios where test range instrumentation is not available such as over rugged mountainous terrain or in crowded urban areas.
Of course, if a launcher is used to carry a form-fit instrumentation package, the missile may be incapable of being fired. This is not as limiting as one might think, however. Most flight testing of expensive missiles is done in a xe2x80x9ccaptive carry,xe2x80x9d so the opportunity for significant use of a preferred embodiment of the present invention, i.e., the modified launcher, is great. Thus a specific application of a preferred embodiment of the present invention lies in acquiring and recording data during captive carry flight testing of a system, specifically an expensive missile. Of course, the data must be reviewed and analyzed at some point, hence, also provided is a portable downloader to capture the data from the aircraft once it has landed. This download capability is facilitated by rugged connectors, to pre-specified limits of environmental stress both internal to the pod and external to the downloader, for connecting cabling from the modified launcher pod to the downloader. Further, data may be presented to an operator in real time, such as a pilot or a weapon system operator, thus facilitating real time re-direction of a mission.
The instrumentation package may be powered by batteries carried within the launcher pod, by power provided by the platform, such as a high performance aircraft, or a combination thereof. The digital recorder may be a xe2x80x9cbankxe2x80x9d of memory cards that, in toto, represent a digital recorder. The cards may comprise flash memory, such as flash RAM, of 6 GBytes (GB) or more, enough to record a typical one-hour captive carry flight test of a modern missile carried on a high performance aircraft.
Since some of the data may need to be converted to analog, e.g., to be used for real time video display in the cockpit, the circuitry may comprise one or more digital-to-analog (D-A) converter circuits. For conventional, older generation systems, analog-to-digital circuits may be used. In addition to the data provided from existing systems onboard the aircraft and the missile, additional sensors may be added and tied in to the instrumentation for purposes of collecting enhanced data such as would be useful to describe unique test conditions, implementation of supplemental systems, or prototype improvements to the missile or aircraft systems.
Since the instrumentation package, in a preferred embodiment, will be used with military systems, utilization of a MIL-STD-1553 data bus for transfer of data is preferred. Because the data will be used to measure dynamic performance, precise timing may be provided using the InterRange Instrumentation Group (IRIG) standard for both actual and pseudo-timing.
One embodiment visualizes a missile launcher affixed to an aircraft incorporating onboard sensors and electronics as part of an integrated weapon delivery system. An example structure is a LAU-7 missile launcher pod for launching the AIM-9 SIDEWINDER air-to-air missile from a high performance aircraft such as an F/A-18. The LAU-7 is a good choice for modification to accept an instrumentation configuration because it is flight certified as to strength, weight, center of gravity (COG), and Moment of Inertia (MOI). A primary need exists for xe2x80x9ccaptive carryxe2x80x9d testing of an AIM-9X missile as well as any follow-on designs based on the AIM-9X. U.S. Navy predecessor versions of the AIM-9X required the N2 bottle 120 for cryogenic cooling of the missile""s IR detector while the missile was operating onboard the aircraft in an acquisition or search mode. As-built modifications, per a preferred embodiment of the present invention designated In-Flight Data Acquisition Pod (I-DAP), may permit operation with minimal further certification.
In addition to instrumentation to be housed within an existing structure, provided is a method for configuring the instrumentation package as a conforming assembly within an existing certified structure. A preferred embodiment of the present invention is designed and built by:
measuring available space within the interior of the structure;
designing electronics modules with connectors and cabling to fit within the structure;
fabricating the modules, connectors and cabling; and
packaging the modules, connectors and cables to withstand severe environmental conditions and to fit within the available space as the instrumentation package described above.
The instrumentation package may be installed without changing the external physical configuration of the structure or the platform, and may minimize requirements for additional certification of the structure as modified internally by said instrumentation package. Assuming the existing structure holds at least one component, installed components may be removed along with any supporting structure unique to them. Provision is made for ready download of data acquired during operation of a system onboard the platform through a compatible connector and cabling to an off-platform downloader, i.e., a portable data acquisition system, or downloader, made available for downloading data at the end of a test. Additionally, a capability may exist to provide at least some of the data to an operator of the platform or vehicle in real time, through installation of appropriate circuitry, connectors, and cabling and provision of suitable power.
Advantages of preferred embodiments of the present invention, as compared to conventional systems, include permitting:
use of commercial off-the-shelf components (COTS) for at least part of the configuration;
conservation of test resources;
reduced time for test preparation;
improved data quality;
reduced (or eliminated) need for telemetry;
improved data security;
standardized configuration;
ready adaptation of existing flight-certified configurations;
simplified test sub-systems using COTS hardware where possible;
simplified design of alternate configurations;
inexpensive fabrication;
reduced man-hours for operation;
reduced system complexity;
reduced system capital costs;
improved robustness;
low maintenance costs;
increased flexibility;
high reliability;
use of existing flight-certified connectors;
use of HOTLink(trademark) standard serial digital video and manchester-encoded serial telemetry (TM) data;
form-fit within a launcher to replace an item(s) not needed during captive carry testing such as the internal N2 bottle used to assist with external cryogenic cooling of the seeker head of early versions of the AIM-9 SIDEWINDER that is not needed by the internally-cooled AIM-9X;
adaptation and use of modules while allowing full functional communication between the aircraft and the captive missile;
no approval needed for authorized frequencies and broadcast times since TM can be shutoff and all recording done internally;
mobility and maneuverability of the aircraft is enhanced since there is no concern about xe2x80x9cblankingxe2x80x9d a ground telemetry site;
mechanical, structural, electrical, shock, thermal management, power management, and environmental constraints to pre-specified limits of environmental stress both internal to the pod and external to the downloader are met with minimal certification; and
ready upgradability.
Embodiments of the present invention can be applied to non-airborne platforms including those operating above and below terra firma and the water""s surface. Thus, it can be applied to other than military operations to include mining, recreation, geologic and oceanographic surveys, etc. Finally, a preferred embodiment of the present invention may be used in realistic training, providing feedback that otherwise might be available only from a less objective source, such as operator debriefing, thus providing more accurate and easily interpreted data for training and updating.
Preferred embodiments are fully disclosed below, albeit without placing limitations thereon.